How do I know if 5G is working Samsung S21?

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Check with your carrier to make sure you have the correct data plan . Also, make sure you are using the SIM card that came with your phone or a 5G compatible SIM provided by your carrier. Older SIM cards may not be compatible with 5G plans. You can check Network mode to make sure that your phone has 5G enabled.

Check your phone’s display . Whenever 5G coverage is not available, your phone will automatically fall back to 4G or 3G speeds. Check to see if your phone is displaying the 5G indicator on the status bar.